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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <script>
   (function(x){
     return (function(y){
         console.log(x);
     })(2)
   })(1); 
   //函数的闭包  内部函数仍然可以访问外部函数的变量
   </script>
</body>
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